[Gioacchino La Rochelle]

I agree with this message.

My work proceeds what expressed in this topic time ago.

I need to model subcooled liquid evaporation up to superheater steam. I am using IAPWS-IF97 tables for saturation.

Driven by suggestions on this forum I did not get into a full-multiphase model (continuous+dispersed steam droplets) but assigning to the domain the Homogeneous Binary Mixture of H205lv, intended as continuous phase. I solved the famous error of table clipping by enlarging the tempeature domain of interpolation of steam tables, as suggested in the previous posts.

For now, my steady state results fit properly the by-hand calculations in terms of development of the flow at regime and I am quite happy for it. I have even included the Buoyancy terms (simple Businesque model assuming as reference density the avg in the domain).

Here to report and ask the forum some tips on for troubles:
• convergence velocity: for steady state simulation I need more than 1500 iteration to get RMS<1e-4. Due to Buoyancy approach I am using a Physical Time Scale of the order or 1e-3 s. By increasing it, the convergence seem faster (i.e. in terms of imbalances) if many hundreds of iterations are already done. Turbulence modelling (SST) and heat transfer are the equation more slow to solve.
• transient simulation: Using as timestep 1e-5 I don't get overflow, as soon as the timescale increase to 1e-3 I get overflow (even with a Courant Number below 1!). Checking the results, it seems that the subcooled regime is not evaporating but stopping on the steam ahead. I have not knowledge of advanced heat transfer model, but what I don't get from transient is exactly the expected evaporation for liquid flowing impacting resting steam domain. I have tried vary initialization, even simple with laminar flow.